Fuel compositions



' atom contributing one electron.

United States Patent ice 3,155,62tl FUEL (IUMPQSHTTONS Rex D. Closson,Royal flak, Thomas H. (Iofiield, Farmington, and ()skar E. H. Klopter,Bloomfield Hills, Mich, and Hymin Shapiro, Baton Rouge, Lac, assiguorsto Ethyl Corporation, New York, N.Y., a corporation of Virginia NoDrawing. Filed 0st. 3, 1962, Ser. No. 229,162

3 Ciaims. (Cl. 252--49.7)

This invention relates to hnproved liquid hydrocarbon compositions andmore particularly to such compositions containing an organometallicadditive.

This application is a continuation-in-part of application Serial No.735,710, filed May 16, 1958. It is an object of this invention toprovide improved liquid hydrocarbon compositions. Another object is toprovide an improved fuel containing a particular class of organometalliccompounds as additives. A further object is to provide fluids foraddition to fuels to improve the combustion characteristics thereof.Another object is to provide improved lubricating oil compositions.Still other objects will be clear from the following description of theinvention.

The present invention is directed to the use of cycloheptatrienetransition metal coordination compounds of the Group VIB metals, asadditives for liquid hydrocarbon compositions.

The coordination compounds employed as additives in the instantinvention constitute coordination compounds having a cycloheptatrienecompound coordinated with a transition metal of Group VIB of thePeriodic Table. Further stabilization of the aforementioned transitionmetal containing compounds can be effected through additionalcoordination with other electron donating groups or anothercycloheptatriene molecule. The sum of all electrons donated to thetransition metal and the atomic number of said metal in the additive compounds is equal to the atomic number of the next higher rare gas withrespect to said metal. Most preferred compounds may be represented bythe formula:

AM(CO) where A is a cycloheptatriene compound coordinated to the groupVlB metal atom M. Examples of these compound-s are the cycloheptatrienechromium tricarbonyls, cycloheptatriene molybdenum tricarbonyls and thecycloheptatriene tungsten tricarbonyls and the like.

Before illustrating the use of the cycloheptatriene coordinationcompounds as additives according to this invention, it is convenient tofurther define the scope of the coordination compounds. The termcoordination as employed in this invention means the electron donatingmechanism by which an inert gas tsructure in the outer electron shell ofthe metal atom is achieved. Thu-s, the term coordinated can be definedas non-ionic bonding including both covalent and coordinate covalentbonding. By covalent bonding is meant a bond formed by the sharing oftwo electrons between bonded atoms, each By coordinate covalent bondingis meant a bond in which two or more electrons are shared by the bondedentities but one entity supplies all bonding electrons.

The compounds employed in the compositions encompassed by this inventioncan consist of two or three primary constituents. The most preferredcompounds have three primary constituents a cycloheptatriene molecule,the Group VIB metal atom and three carbonyl groups. Other preferredcompounds may possess electron donor groups other than the carbonylgroup, e.g. compounds such as cycloheptatriene chromium benzene andcycloheptati'iene molybdenum toluene are applicable.

3,155,620 Patented Nov. 3, 1964 Another type of compound suitable foruse according to the invention are the bis(cycloheptatriene) Group VlBmetal compounds. A suitable combination of donors, producing the maximumpossible covalency on the metal atom will produce the desired type ofcoordination compounds of this invention. In the compounds the sum ofall coordinated electrons of each transition metal plus the atomicnumber of said metal is equal to the atomic number of the next higherrare gas with respect to the metal. It is to be noted that thecycloheptatriene compound, the other electron donors and the metalelectron acceptor are the sole substituents of the compounds.

The coordination compounds employed as additives in this invention aremetallic coordination compounds in which the metal is a transition metalselected from Group ViB of the Periodic Chart of the Elements as shownin the Handbook of Chemistry and Physics, 38th edition, The ChemicalRubber Publishing Co, Cleveland, Ohio, 1956. These metals are chromium,molybdenum and tungsten.

Another primary constituent of the additive compounds of the presentinvention is a cycloheptatr iene compound. Cycloheptatriene is aconjugated cyclic hydrocarbon having 3 :carbOn-tocarbon double bonds ina 7 carbon atom ring. The compound has the formula C H It can berepresented by the following formula:

The cycloheptatriene compound which is a constituent of the compoundsused in this invention can be selected froma wide range ofcycloheptatriene organic compounds. The applicable compounds include,for example, cycloheptatriene, 1 cycloheptatrienyl cycloheptatriene, 1methylcycloheptatriene, 2 isopropylcyoloheptatriene, 1,4di-e-thylcycloheptatriene, 4 phenylcycloheptatriene,S-decylcycloheptatriene, 1-tert-butylcycloheptatriene, 1,3-diisophopylcycloheptatriene, 1 hydroxycycloheptatriene,l-cycloheptatr-ienyl carbo-xylic acid propylester, 3-cycloheptatrienylbutylether, 2-N-cthylcycloheptatrienyl amine,1-methylaminocyclohelptatriene, 1-chlorocycloheptatriene,3,S-di-methoxycycloheptatriene, l-di-methoxymethylcycloheptatriene, 3isopropyl 1 phenylcycloheptatriene, lmethyl-4-phenylcycloheptatriene, 3hydroxymethylcycloheptatriene, l-cyclohcptatriene carboxylic acid,l-cycloheptatriene and the like. Those compounds having up to about 14carbon atoms are preferred since they lead to more easily recoverableproducts and constitute the most readily available cycloheptatrienecompounds.

The third primary constituent of the new compositions of matter of thepresent invention is designated as an electron donating group capable ofcoordinating with the metal atom in the novel compounds of thisinvention and donating thereto 1 through 6 electrons each. This is tosay, that these groups are capable of sharing electrons with the metalatom so that the metal achieves a more stable structure by virtue of thecoordination.

The electron donating groups applicable to the compounds of thisinvention may either be organic or inorganic entities which are capableof existing as ions, such as hydrogen, the cyanide groups, isocyanidegroup, alkyl, and the like. For the sake of clarity, the electrondonating group can best be described by combining these groups accordingto the number of electrons they are capable of donating. The electrondonors are discussed below.

The Group VIB metal atoms in the additive compounds have the electronicconfiguration of the next higher inert gas. Preferably the metal atomsalso have a coordination number of six, or in other Words six pairs ofcoordinated electrons are donated to the central metal atom. Thesepreferred compounds are in general, more readily prepared and of higherstability.

One type of preferred compounds contains two rings, which each donatethree pairs of electrons. Non-limiting examples of this type ofcompounds are cycloheptatriene molybdenum benzene and decycloheptatrienechromium.

Another type of preferred compounds are those that contain acycloheptatriene ring (which donates three electron pairs) and threemoles of a two-electron donor. Of the two-electron donors describedbelow, carbon monoxide is preferred. Thus the more preferred compoundsare the cycloheptatriene chromium tricarbonyls the cycloheptatrienemolybdenum tricarbonyls and the cycloheptatriene tungsten tricarbonyls.The metal atoms in these compounds have the preferred coordinationnumber, six, since the cycloheptatriene donates three pairs of electronsand the 3 carbonyl groups each donate one pair.

The cycloheptatriene Group VIB metal tricarbonyls are more preferredthan the two ring compounds described above since they are more readilyprepared.

Other cycloheptatriene Group VIB metal compounds that contain electrondonors of the type described below which do not have a coordinationnumber of six are suitable but not preferred.

Donors capable of sharing a single electron with a metal atom includemonovalent organic radicals such as the hydrogen atoms, the halogens(fluorine, chlorine, bromine, iodine) and the cyanide group CN. Thesegroups function as electron donors by combining an electron with anelectron of the metal atom to form a single covalent bond. It is to benoted that when the electron donor group bonded to the metal atom in acompound of this invention is or contains a monovalent organic radicalthis organic radical can contain up to about 20 carbon atoms. In mostinstances, such monovalent organic groups are hydrocarbon or substitutedhydrocarbon groups containing between 1 and 16 carbon atoms. Thesepreferred organic radicals include alkyl, aryl, alkaryl, aralkylradicals and the like. Furthermore, acyclic un saturated derivatives canbe employed such as alkenyl and alkynyl derivatives. Such substituentsas nitro, amino, amido, thio, sulfate, carboxy, carbamide, oxy, hydroxy,alkoxy, aryloxy, and their corresponding thio derivatives may be presenton the hydrocarbon radical. In general, however, those substituentspreferred are those containing chalkogen, that is, oxygen or sulfur, andnitrogen atoms, such as the foregoing nitro, nitroso, amino, oxy,hydroxy, thio groups. Specific examples of those hydrocarbon groupspreferred as monovalent organic substituents in the compositions of theinstant invention are methyl, ethyl, propyl, octyl, 4-phenyl octyl,Z-phenyl heptyl, eicosyl, l-nitropropyl, 3-amino-n-octyl, and the like.Illustrative of compounds containing donors capable of sharing a singleelectron with a transition metal atom are cycloheptatriene(cyclopentadienyl) chromium methyl, cycloheptatriene molybdenum(diethyl) dicarbonyl and the like.

Groups capable of sharing two electrons with a metal atom include carbonmonoxide, ammonia, primary-, secondary-, and tertiary-amines, cyclicnitrogen compounds wherein the nitrogen is in the trivalent state,organo phosphine compounds, phosphines, halides, arsines, stibines,bismuthines; mixed hydroorganic phosphines, stibines, arsin, andbismuthines; isonitriles, and the like. Examples of the metalcoordination compounds of this invention which contain such donatinggroups include cycloheptatriene molybdenum tricarbonyl dimer,cycloheptatriene chromium tris(triphenylphosphine) cycloheptatrienechromium bis(methyl isonitrile), carbonyl and the like.

The nitrosyl group, NO, is an example of an entity capable of donatingthree electrons to a metal atom. Examples of compounds containing groupsof this nature include cycloheptatriene tungsten dinitrosyl,cycloheptatriene chromium dinitrosyl, and the like.

Cir

In the coordination compounds employed in this invention certain groupsare capable of coordinating four electrons with the metal atom. Thesefour electron donor groups include organic diamines, diphosphines,diarsines, distibines, aliphatic diolefins, and alkyne molecules.Typical examples of the compounds of the instant invention containingsuch donor groups are cycloheptatriene chromium bis(methylene diamine)carbonyl, cycloheptatriene tungsten( butadiene) carbonyl and the like.

The cyclopentadienyl radical is capable of contributing 5 electrons tothe coordination compounds utilized in this invention. Thecyclopentadienyl radical found in the compounds contains from 5 to about13 carbon atoms and thus includes substituted cyclopentadienylhydrocarbon radicals having up to 8 carbon atoms in one or more sidechain substituents which may be bonded to more than one ring carbonatom. Examples of such radicals include the octylcyclopentadienylradical, the methylcyclopentadienyl radical, the indenylcyclopentadienylradical and the like. Examples of the compounds employed in thisinvention which contain a cyclopentadienyl radical includecycloheptatriene cyclopentadienyl chloromolybdenum, cycloheptatrieneethylcyclopentadienyl ethyltungsten and the like.

Aromatic compounds, that is, compounds containing a benzene nucleus, arecapable of coordinating with a metal atom. These aromatic compounds actas 6 electron donors when coordinately bonded to the metal atom. Aryland alkyl substituted aromatic compounds are applicable to the presentcompounds, as are fused ring compounds having a benzene nucleus.Aromatic compounds having rom 6 to 18 carbon atoms are generallypreferred in the present compounds. Examples of these are benzeneitself, mesitylene, toluene, biphenyl tetraline and m-hexyL biphenyl.Examples of the present compounds containing an aromatic coordinatinggroup include l-ethylcycloheptatriene (toluene) molybdenuml-phenylcycloheptatriene (mesitylene) tungsten, cycloheptatriene(ethylbcnzene) chromium, and the like.

The new compositions of matter of the instant invention comprise aliquid hydrocarbon containing from about 0.015 to about 10 grams pergallon of a transition metal of Group VIB. The metal is employed as acycloheptatriene coordination compound as defined above. It is foundthat when such compositions are employed in the operation of an ignitioninternal combustion engine, advantages are achieved which are unrealizedin compositions which do not contain the compounds. Additionally, theyare useful in other hydrocarbon stocks such as jet fuel, diesel fuel andheating fuels and lubricants.

A preferred composition of the present invention comprises a compositioncontaining from about 0.03 to about 6 grams of a Group VIB metal pergallon of fuel as a cycloheptatriene coordination compound. This rangeof metal concentration is preferred as it is found that superior resultsstem from its use.

A particular advantage of the additives of the present invention is thefact that by proper selection of the coordinating groups, that is, thecycloheptatriene and other dilferent electron donors, compounds havingtailor-made characteristics can be obtained. Thus, by the properselection of the coordinating group it is possible to prepare compoundspossessing different degrees of stability, volatility, and solubility.Likewise, the selection of these constituents also enable thepreparation of compounds of applicability in diverse liquidhydrocarbons.

The compounds employed in this invention can be used in fuels andlubricating oils by themselves or together with other additivecomponents such as, in the case of gasoline, scavengers, depositmodifying agents containing phosphorus and/ or boron, and also otherantiknock agents, such as organolead compounds. For example, fuelscontaining organolead antiknock agents can contain from about 0.01 toabout 8 or more grams of lead per gallon.

The compounds can be added directly to the hydrocarbon fuels orlubricating oils and the mixture subjected to stirring, mixing, or othermeans of agitation until a homogeneous fluid results. Alternatively, thecycloheptatriene metal compound may be first made up into concentratedfluids containing solvents such as kerosene, toluene, hexane, and thelike, as well as other additives such as scavengers, antioxidants andother antiknock agents, for example, tetraethyllead. The concentratedfluids can then be added to the fuels. In such manner new compositionsof matter comprising fluids particularly adapted for addition tohydrocarbon fuels can be produced. Such fluids consist essentially of anorganolead antiknock agent, halohydrocarbon scavengers therefor, and acycloheptatriene metal coordination compound of a transition metal ofGroup VIB. When employed in these fluids the cycloheptatriene metalcoordination compound is present in amounts so that for each gram oflead present there is from about 0.01 to about grams of a transitionmetal of Group VIB. A preferred range comprises those compositionswherein the relative concentrations of transition metal are adjusted sothat from about 0.1 to about 6 grams of Group VIB transition metal ispresent for each gram of lead as an organolead compound.

As the organolead antiknock agent which is one of the ingredients ofcertain of the compositions of this invention, organolead compounds ingeneral may be used. Preferably, however, hydrocarbon lead compoundssuch as tetraphenyllead, tetratolyllead, and particularly tetraalkylleadcompounds wherein the alkyl radical contains between 1 to 4 carbonatoms, such as tetramethyllead, tetrapropyllead, and the like areemployed.

When halohydrocarbon compounds are employed as scavenging agents, theamounts of halogen used are given in terms of theories of halogen. A.theory of halogen is defined as the amount of halogen which is necessaryto react completely with the metal present in the antiknock mixture toconvert it to the metal dihalide. In other words, a theory of halogenrepresents two atoms of halogen for every atom of lead present. In likemanner, a theory of phosphorus is the amount of phosphorus required toconvert the lead present to lead orthophosphate, Pb (PO that is, atheory of phosphorus based on lead represents an atom ratio of two atomsof phosphorus to three atoms of lead. When based on chromium, a theoryof phosphorus is equivalent to one atom of phosphorus for every one atomof chromium, that is, sufficient phosphorus to convert chromium tochromium orthophosphate, CrPO Similar considerations apply to the othermetals.

In employing the compounds of this invention together with scavengers,an antiknock fluid for addition to hydrocarbon fuels is preparedcomprising a metal coordination compound together with variousscavengers such as halogen-containing organic compounds having from 2 toabout 20 carbon atoms in such relative proportions that the atom ratioof metal-to-halogen is about 50:1 to 1: 12. The halogen scavengercompounds can be halohydrocarbons both aliphatic and aromatic in natureor a combination of the two with halogens being attached to carbonseither in the aliphatic or the aromatic portions of the molecule. Thescavenger compounds may also be carbon, hydrogen, and oxygen-containingcompounds, such as haloalkyl ethers, halohydrins, haloesters, halonitrocompounds, and the like. Still other examples of scavengers that may beused in conjunction with the novel compounds of this invention eitherwith or without hydrocarbolead compounds are illustrated in US. Patents2,398,281 and 2,479,900-903, and the like. Mixtures of differentscavengers may also be used. These fluids can contain other componentsas stated hereinabove. In like manner, fluids are prepared containingfrom 0.01 to 1.5 theories of phosphorus in the form of phosphoruscompounds. To make up the finished fuels,'the concentrated fluids areadded to the hydrocarbon fuel in the desired amounts and the homogeneousfuel obtained by mixing, agitation, etc.

The ratio of the weight of metal in the form of a compound of thisinvention to lead in fluids and fuels containing the two components canvary from about 1:880 to about :1. When no lead is present, the latterfigure becomes 1:0. A preferred range of ratios, however, when both thecompounds of this invention and hydrocarbolead compounds are employed,is from about 1:63 to about 30:1.

The following examples are illustrative of fuels and fluids containingthe coordination compounds described herein above.

Example I To 1000 gallons of a commercial fuel having an initial boilingpoint of 90 F. and a final boiling point of 406 F. is added 15 grams ofchromium as cycloheptatriene chromium tricarbonyl and the mixture issubject to agitation until the additive is distributed evenly throughoutthe fuel in an amount equivalent to 0.015 gram of chromium per gallon offuel.

Example [I To 1000 gallons of the commercial fuel utilized in Example I,is added 600 grams of chromium as cycloheptatriene chromium tricarbon-yland 40 grams of methylcycloheptatriene molybdenum benzene. The mixtureis then subject to agitation until the additives are distributed evenlythroughout the fuel in amounts equivalent to 0.6 gram of chromium pergallon of fuel and 0.04 gram o molybdenum respectively.

Example III To 10 parts of lead in the form of tetraethyllead in anantiknock fluid containing 0.5 theory of bromine as ethylene dibromideand 1.0 theory of chlorine as ethylene dichloride wherein the theoriesof halogen are based upon the amount of lead present, is added 0.1 partof molybdenum in the form of chlorocycloheptatriene molybdenumtricarbonyl.

This fluid is then added to a commercial fuel having an initial boilingpoint of 82 F. and a final boiling point of 430 F. in an amount so as toprovide 10 grams o lead and 0.1 gnam of molybdenum per gallon.

Example IV Into a fuel containing 0.1 gram of lead per gallon asdiphenyl diethyllead, 1 theory of bromine as ethylene dibromide, and 0.2theory of phosphorus in the form of tricresyl phosphate is addedcycloheptatriene tungsten tricarbonyl in an amount equivalent to 1 gramof tungsten per gallon.

Example V Eight grams of chromium per gallon as l-phenylcycloheptatriene chromium tricarbonyl is added to a gasoline having aninitial boiling point of 116 F. and a final boiling point of 385 F. andwhich contains 70.1 percent parafiins, 15.6 percent olefins, and 14.3percent aromatics.

Example VI To 1000 gallons of a commercial fuel having an initialboiling point of 88 F. and a final boiling point of 390 F. is added10,000 grams of molybdenum as cycloheptatriene molybdenum tricarbonyltitanium and the mixture subjected to agitation until the additive isdistributed evenly throughout the fuel in an amount equivalent to 10grams of molybdenum per gallon of fuel.

Certain of'the fuels containing the cycloheptatriene metal coordinationcompounds as additives contain mixtures of two or more of thesecoordination compunds containing similar metals, however consisting ofdissimilar compositions in that various coordination substituents areadfixed to these similar metals.

Example VII To a gasoline having an initial boiling point of 8-6 F.

7 and a final boiling point of 419 F. is added 60 grams of chromium ascycloheptatrienyl cycloheptatriene chromium tricarbonyl and 3 grams ofchromium as bis- (cycloheptatriene) chromium and the mixture subjectedto agitation until the additives are distributed evenly throughout thefuel in an amount equivalent to about 0.063 gram of chromium per gallonof fuel.

The following examples illustrate the preparation of fluids containingthe coordination compound additives of this invention.

Example VIII To 10 parts of ethylphenyl cycloheptatriene chromiumtricarbonyl is added 5 parts of ethylene dichloride and the mixtureagitated until a homogeneous fluid results.

Example IX A fluid is prepared comprising bis(cyclohexyl-cycloheptatriene) tungsten and ethylene dibrornide in whichthe tungsten to bromine ratio is 1:8.

Example X A fluid containing 3,5-dimethylcycloheptatriene tungstentricarbonyl, ethylene bromohydrin, and 2,3-dichloro- 1,4-dimethylbenzene is prepared in such proportions that for every 75 atoms oftungsten there are 1 atom of bromine and 2 atoms of chlorine.

The above fluids are added to hydrocarbon fuels in amounts so as toprovide fuels containing 0.015 gram, 0.03 gram, 6 grams and 10 grams oftransition metal per gallon.

Example XI To 13.2 parts of lead in the form of tetraethyllead in anantiknock fluid containing 0.5 theory of bromine as ethylene dibromideand 1 theory of chlorine as ethylene dichloride wherein the theories ofhalogen are based upon the amount of lead present is added 0.015 part ofmolybdenum in the form of cycloheptatriene molybdenum tricarbonyl.

The fluid is then added to a commercial hydrocarbon fuel having aninitial boiling point of 96 F. and a final boiling point of 410 F. in anamount so as to provide 13.2 grams of lead and 0.015 gram of molybdenumper gallon.

Other fuels and fluids are prepared in the same manner as illustratedherein above which contain other deposit modifying agents, such as boricacid, borate esters, boronic esters, etc. Likewise, lubricating oils canbe prepared containing from about 0.1 to about 5 weight percenttransition metal in the form of the cyclic conjugated olefincoordination compounds described thereinbefore. These lubricating oilswhen used in reciprocating engines were found to have a beneficialeffect on engine cleanliness and in the reduction of combustion chamberdeposits. In particular those embodiments of the additives of thisinvention wherein a metal such as molybdenum is associated with sulfurimpart improved antiwear characteristics to the lubricant base stock.

The fuels to which the additive compositions of this invention are addedmay have a wide variation of compositions. These fuels generally arepetroleum hydrocarbons and are usually blends of two or more components.These fuels can contain all types of hydrocarbons including paraifins,both straight and branched chain; olefins; cycloaliphatics, containingparafiin or olefin side chains; and aromatics containing aliphatic sidechains. The fuel type depends on the base stock from which it isobtained and on the method of refining. For example, it can be astraight run or processed hydrocarbon including thermally crackedcatalytically cracked reformed fractions, etc. When used for spark firedengines the boiling range of the components of gasoline can vary from 0to about 430 F. Although the boiling range of the fuel blend is oftenfound to be between an initial boiling point of from 80 F. to 100 F. anda final boiling point of about 430 F. The above being true for ordinarygasoline the boiling range is a little more restricted in the case ofaviation gasoline. Specifications for the latter often call for aboiling range of from about 82 F. to 338 F. with certain fractions ofthe fuel boiling away at particular intermediate temperatures.

To illustrate the antiknock effect of the cycloheptatriene metaladditives of this invention tests are conducted by the Research Methodof determining octane number. The Research Method of determining theoctane number of the fuel is generally accepted as a method of testswhich gives a good indication of fuel behavior in full scale automotiveengines under normal driving conditions and the method most used bycommercial installations in determining the value of a gasoline oradditive. The Research Method of testing antiknocks is conducted in asingle cylinder engine especially designed for this purpose and referredto as the CFR engine. This engine has a variable compression ratio andduring the test the temperature of the jacket water is maintained at 212F. and the inlet air temperature is controlled at 125 F. The engine isoperated at a speed of 600 rpm. with a spark advance of 13 before topdead center. The test method employed is more fully described in thetest procedure D908-55 contained in the 1956 edition of ASTM Manual ofEngine Test Methods for Rating Fuels. The tests are conducted in acommercial fuel having an initial boiling point of 85 C. and a finalboiling point of 420 C. Significant octane increase results are obtainedwhen the Group VIB transition metals as the compounds described in thisinvention are employed in varying amounts to a multitude of diversefuels as taught hereinbefore.

Another advantage which certain additives of this invention possess istheir ability, when properly employed, to reduce the wear ordinarilyencountered in engines. The amount of wear can be determined by the rateof loss of weight by the upper piston ring according to the methoddisclosed in US. Patent 2,315,845. The method of this patent tinvolvesdetermining wear by incorporating a radioactive substance in the surfaceof the piston ring normally subjected to abrasive wear, then abradingthe surface in the presence of the lubricating oil which is capable ofreceiving abraded particles, and then determining the radioactivity ofthe lubricating oil. Thus, the wear is determined after operation of theengine containing the radioactive piston rings. It is found that whencertain compositions of this invention are employed, considerably lesswear is evidenced than in the absence of these compounds.

Examples of the hydrocarbon lubricating compositions of this inventioninclude the following.

Example XII To 10,000 parts of a petroleum hydrocarbon lubricating oilhaving an API gravity at 60 F. of 30.3, a viscosity at F. of 178.8 SUS,a viscosity index of 154.2 and a pour point of -30, is suificient3-ethylcycloheptatriene molybdenum tricarbonyl to give a compositioncontaining 5 percent molybdenum.

Example XIII To a petroleum hydrocarbon oil having a viscosity at 60 F.of 30.5" API, a viscosity at 100 F. of 373.8 SUS, a viscosity index of107.4, is added sufiicient l-phenylcycloheptatriene chromium tricarbonylto give a composition containing 0.1 percent chromium.

Example XIV To a quantity of an oil having a viscosity of 169.0 SUS at100 F. and a gravity of 31.1 API at 60 F., is added sufficientcycloheptatriene tungsten tricarbonyl to give a composition containing 4percent tungsten.

In the compositions of this invention effective use can be made of otheradditives which are known to the art, such as inhibitors,detergent-dispersants, pour point dcpressants, viscosity indeximprovers, anti-foam agents, rust inhibitors, oiliness or film strengthagents, dyes, and the like. Of the inhibitors which can be effectivelyused in combination with the compounds of this invention are sulfurizedsperm oil, sulfurized terpenes, sulfurized paraffin wax olefins,aromatic sulfides, alkyl phenol sulfides, licithin, neutralizeddithiophosphates, phosphorus pentasulfideterpene reaction products,diphenylamine, phenylnaphthyl amine, B-naphthol, pyrogallol, and thelike. Typical of the detergent additives that can be used in thelubricant compositions of this invention are metallic soaps of highmolecular Weight acids, such as aluminum naphthenates, calcium phenylstearates, calcium alkyl salicylates, alkaline earth metal petroleumsulfonates, alkaline earch metal alkyl phenol sulfides (barium amylphenol sulfide, calcium octyl phenol disulfide, etc.), metal salts ofwax-substituted phenol derivatives, and the like. Of the viscosity indeximprovers and pour point depressants, effective use can be made ofpolymers of the esters oi methacrylic acids and higher fatty alcoholsand the corresponding polymers of esters of acrylic acid and higherfatty alcohols. These and other additives which can be employed in thelubricant compositions of this invention will now be well known to thoseskilled in the art.

A procedure which can be employed in preparing the compounds of thisinvention involves the reaction between a compound of the type MXYwherein M is a transition metal as defined hereinabove and X and Y areelectron donors such as those defined hereinabove which can be the sameor different, with a cycloheptatriene compound.

The Wide variation of pressures and temperatures can be employed in theabove process dependent upon the reagent used and the reaction productdesired. For example, temperatures of the range of 100 C. can beemployed in the preparation of cycloheptatriene chromium tricarbonyl. Ingeneral, however, the aforementioned process employs temperaturesranging between about 50 to 500 C. Generally pressures ranging fromatmospheric to 10,000 p.s.i. can be employed, however, in mostinstances, the pressure reaction vessel is employed and autogenouspressure utilized. Solvents generally are not employed in this process,however, are in some instances desirable to insure reaction control andthe like.

In the working examples which appear hereinafter, all parts andpercentages are by weight unless otherwise specified.

Example XV Into a pressure vessel is introduced 264 parts of molybdenumhexacarbonyl and 92 parts cycloheptatriene. The

system is closed and heated under autogenous pressure. Following coolingof the autoclave the CO pressure is bled off to atmospheric pressure andthereafter the product cycloheptatriene molybdenum tricarbonyl isremoved. The crude cycloheptatriene molybdenum tn'carbonyl may befurther purified by sublimation onto a cold finger.

Example XVI Example XVII The process of Example XV is repeated using1000 parts of toluene as a solvent.

Example XVIII Following the procedure of Example XVI with the exceptionthat 352 parts of tungsten hexacarbonyl is employed in place of 264parts of molybdenum hexacarbonyl, 1000 parts of dioxane is utilized as asolvent, and

a temperature of C. is maintained on the system during the course ofreaction thereby the desired product cycloheptatriene tungstentricarbonyl is produced.

We claim:

1. A composition consisting essentially of a liquid bydrocarbon selectedfrom the class consisting of hydrocarbon fuels and hydrocarbonlubricants containing from about 0.015 to 10 grams of a Group VIBtransition metal per gallon as a compound having the formula AM(CO)wherein M is an atom of a Group VIB metal and A is a cycloheptatrienemolecule coordinated to said metal atom.

2. The composition of claim 1 where the additive is cycloheptatrienemolybdenum tricarbonyl.

3. The composition of claim 1 where the additive is cycloheptatrienechromium tricarbonyl.

References Cited in the file of this patent UNITED STATES PATENTS2,150,349 Van Peski et a1 Mar. 14, 1939 2,818,416 Brown et a1. Dec. 31,1957 2,849,471 Thomas Aug. 26, 1958

1. A COMPOSITION CONSISTING ESSENTIALLY OF A LIQUID HYDROCARBON SELECTEDFROM THE CLASS CONSISTING OF HYDROCARBON FUELS AND HYDROCARBONLUBRICANTS CONTAINING FROM ABOUT 0.015 TO 10 GRAMS OF A GROUP VIBTRANSITION METAL PER GALLON AS A COMPOUND HAVING THE FORMULA AM(CO)3WHEREIN M IS AN ATOM OF A GROUP VIB METAL AND A IS A CYCLOHEPTATRIENEMOLECULE COORDINATED TO SAID METAL ATOMS.